rennerfelt



G. RENNERFELT.

APPARATUS FOR CONTROLLING NOVEIIENTS OF ELECTRIC ELEVATOR CARS.

' (Application Med Jun. 29, 1898.) 0 "0 9D I 2 Sheets-Sheet l.

Patented May [6, I899.-

)Xhtmwoeo awpemtoz 652W af/ I w W 6 ww.-

1n: "cams vzvzns'cu, PHOTO-LITHQ. WBHINOTON, D. c.

No. 625,060. Patented May l6, I899.

' G. RENNEREELT. APPARATUS FOR CONTROLLING IOVEI ENTS OF ELECTRIC ELEVATOR CARS. (Application filed .nm. 20; 1898.) (No Model.) 2 8haeta-Shaet 2.

d FIG.3.

/ llllllllll FIG.4

WITNESSES: INVENTOR 7% Wa /W BY m }-WTTORNEY w: "cams vzrzns co. FHOYO-LITHBU WASHINGTON, D. c,

- UNITED STATES GUSTAF RENNERFELT, OF NEXV YORK, N. Y., ASSIGNOR OF TW'O-THIRDS PATENT OFFICE.

TO ROBERT LUNDELL, OF SAME PLACE.

APPARATUS FOR CONTROLLING MOVEMENTS OF ELECTRIC-ELEVATOR CARS.

SPECIFICATION forming part of Letters Patent N0. 625,060, dated May 16, 1899.

Application filed January 29, 1898. Serial No. 668,373. (No model.)

To all whom it may concern:

Be it known that I, GUSTAF RENNERFELT,

I a subject of the King of Sweden and Norway,

residing at New York, in the county of New York and State of New York, have made a new and uscfullmprovementin Apparatus for Controlling the Movements of Electric-Elevator Cars, of which the following is a specification.

My invention has for its objects, first, the pro vision of means whereby the car of an electric elevator may be caused to stop at the proper time on approaching a floor or landing; second, to provide means whereby the speed of a car may be properly regulated when the weight thereof and its load is such as to cause the motor to act as a generator, and, third, to provide meanswhereby a retarding force may be automatically applied upon the too-sudden starting of the car or when the momentary acceleration thereof is beyond a normal or stated speed.

My invention will be fully understood by referring to the accompanying drawings, in which Figure l is a diagrammatic View illustrating all of the electrical circuits and necessary attachments foraccomplishing the objects for which the invention was devised. Fig. 2 is a transverse sectional view taken through the body of my novel means for automatically applying a retarding force upon a too-sudden starting of the car or when the acceleration thereof exceeds a definite limit. Fig. 3 is a detail plan view of the circuit-contacts of the apparatus disclosed in Fig. 2. Fig. 4 is a diagrammatic View illustrating my novel means for automatically regulating the speed of a car when the combined weight of the car and its load is such as to cause the motor to act as a generator. Fig. 5 is a side elevational view thereof as seen looking at Fig. 4 from the right-hand toward the left-hand side of the drawings, the motor being shown in sectional view and the circuit connections not shown.

A fruitful source of trouble in operating electric elevators lies in the difficulty of effecting proper landings or stoppages of the car at the right moment. In order to effect these landings with moderate certainty with existing types of electric elevators, it is customary to employ a single powerful brake applied by a strong spring, which spring is released when the current is turned off, thereby causing the car to be brought to rest. With such a device, however, the retarding force of the brake cannot be varied at the will of the operator. Whether the load on the car be heavy or light and Whether the car he running at high or low speed the brake when applied exerts always the same pressure, and all that the operator can do is to cut off the current a little sooner or a little later, as the case may be, and trust to luck in allowing the elevator-car is compared with the methods of braking or stopping cars traveling in a horizontal direction, it is easily realized that the method here referred to is crude and insufficient.

My invention is designed to overcome, as far as possible, all of the evil effects of existing types of elevator-controlling apparatus, and it will be fully understood by referring to the accompanying drawings, in which- W W represent the current leads or mains running from a dynamo-electric machine (not shown) and W W branch current-leads run ning, respectively, to the switching appara I tus for controlling the circuits of the arma ture A R, and thence through the coils of the brake-controlling magnet D and rheostat F, to w 20 10 &c., to 10 inclusive, representing branch conductors running to the push-buttons 1, 2, and 3, electromagnets and switching-contacts of the controlling-switches L L, H H, G G, K K, shunt field-coil F M, auxiliarybrake-controlling magnet B, and ratchet-controlling magnets Q Q, the aforesaid push-buttons being located in the moving car.

1 2, 1 2, 1 2, 1 2 are switching-contacts for the switches G G and armatureA R, 3 3, 3 3,

4 4, 4 4 being similar switching-contacts for the switches L L and K K.

A represents the electromagnet, which controls the operation of the brake, (not shown, but applied in the usual manner by a spring when released,) the adjustment of this brake being just sufficient to prevent the car from slipping under its maximum load. An anxiliary brake, which is controlled by the coil or magnet B, is applied when necessary, and its retarding force can be varied at the will of the-operator by a rheostat F, carried on the car and located in the circuit w. This rheostat is of sufficient capacity for the small current necessary for operating the brake controlled by said coil, and the operator can by varying its resistance apply the brake controlled by the coil B with more or less force, as he sees fit, so that the same will naturally help him considerably in making his landings and incidentallyon some otheroccasions.

An additional cause of trouble in electricelevator service, especially with socalled overbalanced cars, where the counterweight is of such weight as to just balance the car and the mean or average load which it is supposed to carry, lies in the fact that often a greater speed is attained than is de armature-circuit contains some external resistance, as a pure shunt-wound machine cannot otherwise attain any higher speed than is determined by the voltage of the circuit. In elevator service the motor generally starts up with resistance in the armature-circuit whether it (the motor) needs the current or not, and in the latter case excessive speed may be attained before the attendant has had time to cut the resistance out. With my improvement illustrated in Fig. 1 such abnormally high speed will never occur, since the starting resistance F is automatically short-circuited whenever the motor happens to act as a generator. The manner in which this is accomplished is clearly illustrated in the diagram. A rotary armature C (see also Figs. 4 and 5) of fixed polarity is so designed as to rotate a definite distance by reason of stops .9 s in one or the other direction through the influence of a field-magnet D, energized by the current passing through the armature A R of the motor. To obtain a fixed polarity for the rotary armature O, I magnetize it by passing a current through its commutator-brushes and coils from the main or lead TV through the conductors IV to w, said current running always in the same direction. This rotary armature O is suitably connected, through a crank I), link a, and lever a, to a movable contact E, so that whenever the motor runs as a generator and the current in the field-magnetD assumes sufficient strength in direction opposite to that of the normal direction the contact E willbe moved so as to short-circuit the starting re sistance F by bridging the space between the stationary contacts E and E". (See Figs. 1 and 4.) When the current passes through the field-magnet D in the proper direction, so as to cause the armature A R of the motor to serve its function as a motor, the rotary armature 0 causes the contact E so to move that the starting resistance F will be cut into circuit with the armature of the motor. Excessive speed, caused by the armature A R of the motor being driven as a generator, is thus effectivelyguarded against. Shouldastilllower speed in this case be desired, it can be attained by a gentle application of the auxiliary brake controlled by the coil or magnet B and rheostat F in the circuit 10 w.

An additional feature of my invention is found in my novel manner of closing first the shunt-circuit and afterward the armature-circuit of the motor. This Will be understood by referring to 1, where G is a switch for both terminals of the armature-circuit 1 2 1 2 and is adapted to be closed by energizing the coil H in the circuit 10 10 This coil H is in series relation with the shunt-windings F M of the motor, as shown, and the switch G is so balanced by a spring or by gravity that the current in the shunt-field, and consequently in the coil H, must rise to a certain strength before it the (switch G) will be closed. In this manner I guard against any sudden rush of current through the armature in a nonexcited field. The circuit comprising the coil H-and the shunt-field might be closed by a switch operated by a rope; but in the diagrams I have shown a switch K, controlled by the coils of an electromagnet located in a circuit w 10', running to the push-button 1 in in the elevator-car.

The apparutus disclosed in Figs. 4 and 5 of the drawings, arranged to operate as described, will prevent the motor from attaining any higher than a predetermined speed; but there still remains the possibility that the acceleration or rate of speed increase may become greater than desirable. It is of course true that the operator can at any time he sees fit apply the auxiliary brake controlled by the magnet or coil B, and thus by adding load upon the motor check the speed; but it is preferable that such regulation should occur automatically and instantaneously. For this purpose I have devised an additional apparatus (shown in Fig. 2 of the drawings) consisting of a pulley S and a fly-wheel T, both running loosely on a shaft and joined to-' gether by means of a torsional spring to. The pulley S is driven by a belt from the motor, and it is evident that upon setting this pulley in motion the spring connecting it to the flywheel T will be deflected to a certain degree, depending upon the suddenness of the start.

P is an electrical contact carried by the flywheel T, and R and R additional contacts carried by the pulley S and so located with re: lation to the contact P that when the pulley is revolved in opposite directions with sufiiciently greatacceleration said contact R or R, as the case may be, will be caused to come into electrical contact with the contact P, it being understood that the relation between the weight of the fly-wheel T and the torsional spring 7.6, connectingit to the pulley S, is such that for a predetermined speed of starting the contacts P and R or R will not be brought together. The contact P is connected by proper circuit connections, as shown, to a yielding contact 75, held against the face of a conducting-ring on the fly-wheel T by a spring 3 which in turn is connected to the conductor 20 while the contacts R and R are connected in a similar manner to a metallic disk carried by the pulley S, against which rests a second sliding contact i, yieldingly held against said ring by a conductingspring .9 electrically connected with a conductor N78. The conductors 20 and w are connected one to the conductor w ata pointnear the auxiliary-brake coil B, and the conductor 20 is in turn connected to a shunt-resistance coil 0, so that when the circuit is closed through the contacts P and R or R the auxiliary-brake coil B will be shunted and the brake applied, thereby checking the speed of the car. Several instruments of this sort could be used for shunting more or less of the current, if desired, and thus more or less pressure of the brake put in practice. Probably one or two of such devices, however, would be sufficient. So far as I am aware no such instrument has heretofore been used for such purpose, and my claims in this particular are generic not only as to the apparatus, but to the method of applying the same. This apparatus, which I choose to call an acceloration-controller, is not to be confounded with speed-regulators, which are common in the art. This apparatus does not prevent the speed from varying between any limits, however great. It only prevents the speed from varyingtoo suddenly. \Vithout affectin g the principle of this instrument various modifications may be made in its construction. For instance, the pulley S might be supplied with two fly-wheels, (one on each side,) and the flywheel could be supplied with a brake for the purpose of making it more sluggish, if this should be found desirable. It should be noted that while this instrument prevents a too-sudden starting of the car from a point of rest, it does not prevent a too-sudden stoppage, which I consider a feature of great advantage, since the stopping of a car can and should ordinarily be controlled by the operator alone without any interference from the automatic regulating mechanism.

The operation of the apparatus as illustrated in the diagram is as follows: WVhen the car is to be started, say, upward, the attendant presses push-button 1 in circuit 10 w on the left. Current therefore flows, as indicated by the arrows, through the rotary armature C (see Fig. 4) and the coils of the magnet which controls the switch K back to the current mains or feeds. A branch circuit is also closed through the conductor 10 in the direction of the arrows and the coils of the switch-m agnet L and the rheostat-controlling coil Q. The shunt-field F M is now energized, because the switch K is closed, and when the field is strong enough the armature-circuit A R is closed and the brake controlled by the magnet or coil A released, thus allowing the car to move upward. Should the machine now run as a generator, the contact E will immediately close by virtue of the shunting action of the apparatus illustrated in Figs. 4 and 5, as already described, and the car will hence move more slowly. If it is desired to obtain greater speed, the attendant simply presses the push-button 3 in the circuit 10 10 thereby energizing the controlling-magnet M and causing it to impart. motion to a controllingarm V operatively connected with the rheostat F, thereby cutting out more or less of the coils of said rheostat. This arm continues to advance so long as the push-button 3 is held closed or until the maximum speed is attained, which occurs when it reaches its lower or vertical position and all of the coils are cut out, as will be apparent on inspection of Fig. 1 of the drawings. Ifitis desiredto maintain thespeed of the car constant on ascending, the attendant si mpl y releases the push-button 3 when the desired speed is reached, in which event the controlling-magnet M will be disconnected and the controlling-arm V will be held by the controlling-arm J of the solenoid Q. It will also be apparent on inspection of Fig. 1 of the drawings that should the controlling-arm V be moved in either direction to its bottom limit the circuit will be ruptured as it strikes the weighted switch N, thus limiting the movements of said controlling-arm in opposite directions. This controlling-arm V is held in any desired position of its radial movement by any Well-known form of means, (not shown,) but controlled by either of the levers J J, actuated by the solenoids Q Q in the circuits w 10 and said means is released, as will be understood on inspection of Fig. 1, by actuating the push-buttons 1 0r 2 at the top of Fig. 1 of the drawings, dependent, of course, upon the direction in which the car is being moved. To stop the motor, the attendant simply releases the push-button 1 in circuit w w. The magnetic switch L will then drop quickly, said magnet having a small time-constant. This will short-circuit the winding of the switch H, so that the armature-circuit will be broken before the shunt-field F M is opened. When the arm atu re-circuit is opened, the brake controlled by the coil A is applied by a spring, this brake having been formerly released by the current. ble to move some distance by reason of its Since the car is lia-- IIC momentum, the brake controlled by the coil B is now applied in order to stop at the proper place. A switch N is placed in asuitable location in the circuit 10 for opening the circuit of the coil B, which controls the auxiliary brake, so that its full force will be immediately applied in case the car should travel beyond its proper limits, the necessary limitswitches being of course previously opened.

G L K are the duplicates of the switching apparatus G L K, and 2 the duplicate of the push-button 1, said apparatus being designed for moving the car in a reverse direction, as will be fully understood by noting the circuit relations through the several switches, the armature A R, and shunt field-magnet F M, as seen on the right of the diagram in Fig. 1.

Having thus described myinvention, What I claim, and desire to secure by Letters Patent of the United States, is-- 1. In an electric elevator the combination of a brake adapted to be released automatically by the current with an auxiliary brake adapted to be applied at will, and means for varying the retarding force of said auxiliary brake, substantially as described.

2. In an electric elevator the combination of a resistance in the armature-circuit with means dependent upon the speed of the motor for short-circuiting said resistance when the motor is driven as a generator by the load, substantially as described.

3. In an electric elevator the combination with an electric motor of an acceleration-controller operatively connected with the motor and so constructed as to be inoperative for normal speeds of starting and instantaneously operative for abnormal speeds of starting, said acceleration-controller being operatively connected with means for checking or braking the speed of the car, substantially as described.

4. In an electric elevator an accelerationcontroller mechanically connected with the motor which drives the car, said controller being so constructed as to be inoperative for normal speeds of starting and operative for abnormal speeds of starting and provided with electrical connections running to brake mechanism adapted to instantaneously apply a brake on the too-sudden starting of the car, substantially as described.

5. An electric motor operatively connected with an acceleration-controlling mechanism mechanically connected to the. motor and to a fly-wheel provided with electrical connections and having sufficient moment of inertia to cause the closure of said circuit connections on a too-sudden starting of the motor, the mechanical connection between the motor and the fly-wheel being of yielding nature and adapted to prevent the closure of such circuit on starting the motor at normal speed, substantially as described.

6. An electric motor provided with electromagnetic switching mechanism adapted to close the circuit through the field-magnet coil or coils thereof, in combination With additional electromagnetic switching mechanism adapted to close the circuit through the armature coil or coils thereof, the circuit connections to said sets of electromagnetic switching mechanism being so arranged that the circuit is closed to the field-magnet coil or coils before it is closed to the armature coil or coils, substantially as described.

7. An electric motor provided with electromagnetic means for automatically closing the circuit through the field-magnet coils before it is closed through the armature-coils, in combination with additional electromagnetic means for effecting such closure of the circuit through the armature-coils, substantially as described.

8. An electric motor provided with means for closing the circuit through the field-magnet coils before it is closed through the armature-coils, in combination with electromagnetic means for effecting such closure of the circuit through the armature-coils and additional means for releasing said electromagnetic means, substantially as described.

9. In an acceleration-controller the combination of a fly-wheel and a pulley, with means for checking the speed of the pulley, said means being caused to operate by a variation in the relative positions of the fly-wheel and the pulley, substantially as described.

10. In an acceleration-controller the combination of a fly-Wheel and a pulley with a torsional spring to eifect a variation in the relative positions of fly-wheel and pulley, and means for checking the speed of the pulley, said means being operated by said variation, substantially as described.

In testimony whereof I have hereunto subscribed my name this27th day of January, 1898.

GUSTAF RENNERFELT.

lVitnesses:

O. J. KINTNER, W. P. WVILLIAMs.

IOC 

